A primary school has closed after a “partially collapsed” chalk mine was discovered underneath.

Pinner Wood School, in Latimer Gardens, Pinner, was shut down today by Harrow Council after “shocked” staff and children were deemed to be at risk.

Geotechnical surveys undertaken by Peter Brett Associates and partner Clive Edmonds showed the ground beneath the school buildings and playgrounds could become unstable and unsafe, due to the condition of very recently discovered chalk mine tunnels below.

Laser imaging of these previously “uncharted and unknown” tunnels revealed that they stretch beneath the school buildings and the mine roofs have collapsed in certain places.

These partially collapsed tunnels are likely to open up new surface holes under or near the school at some point in the future.

Pupils will now not return to the school and classes will relocate to other educational places in Harrow in time for the start of the Summer Term.

Deb Spruce, head teacher of Pinner Wood School, said: “This is a huge and sudden shock to all of us. We absolutely need to leave this site until it is made safe.

“Our school is blessed with exceptional staff and governors and a wonderful parent group.

“I’m certain we will all rise to this challenge and show that our school is united by much more than just our buildings.”

Cllr Sachin Shah, the leader of the council added: “With the evidence we have discovered in the past few days, we are certain that this is the right decision.

“We would like to stress that the imminent risk to the school buildings is believed to be small.

“However, the Council would never ask or permit any school to operate when there is a known risk, however small, to the safety of the site or the staff and children within it.”